The present invention relates generally to equipment utilized and operations performed in conjunction with a subterranean well and, in an embodiment described herein, more particularly provides a setting tool for an expandable liner hanger and associated methods.
Expandable liner hangers are generally used to secure a liner within a previously set casing or liner string. These types of liner hangers are typically set by expanding the liner hangers radially outward into gripping and sealing contact with the previous casing or liner string. Many such liner hangers are expanded by use of hydraulic pressure to drive an expanding cone or wedge through the liner hanger, but other methods may be used (such as mechanical swaging, explosive expansion, memory metal expansion, swellable material expansion, electromagnetic force-driven expansion, etc.).
The expansion process is typically performed by means of a setting tool used to convey the liner hanger and attached liner into a wellbore. The setting tool is interconnected between a work string (e.g., a tubular string made up of drill pipe or other segmented or continuous tubular elements) and the liner hanger.
If the liner hanger is expanded using hydraulic pressure, then the setting tool is generally used to control the communication of fluid pressure, and flow to and from various portions of the liner hanger expansion mechanism, and between the work string and the liner. The setting tool may also be used to control when and how the work string is released from the liner hanger, for example, after expansion of the liner hanger, in emergency situations, or after an unsuccessful setting of the liner hanger.
It is desirable to minimize a wall thickness of the setting tool and liner hanger assembly, so that equivalent circulating density (ECD) is reduced, and so that the assembly can be conveyed rapidly into the well.
It will, therefore, be appreciated that improvements are needed in the art of expandable liner hanger setting tools and associated methods of installing expandable liner hangers. These improvements can include improvements to reduce ECD during running in, to increase operational efficiency, convenience of assembly and operation, improved functionality, etc. whether or not discussed above.